The problem of unauthorized access to computer system has made recent headlines and been the subject of major films. The growth of large multi-user computer systems places enormous banks of data at risk of infiltration by persons who may attempt to enter the system merely to demonstrate their computer skills or for personal gain or other advantage. Data bank infiltration can affect activities extending in a wide range, for examples, from military and government security to multi-billion dollar banking transactions, and to changing grades of children at school. Not only may unauthorized persons gain access to computer systems for obtaining and/or modifying the data available therein, but also for destroying such data. Clearly, large institutions, where the stakes are high and the data highly confidential, are reluctant to place their data into computer systems or relocate to other systems that do not include sophisticated precautionary techniques and methods to prevent unauthorized entry to the system. The degree of sophistication required in the security systems continually cranks up as each new system presents a challenge to those who make a specialty of obtaining unauthorized access to computer systems, whether for sport, advantage or profit.
The use of fixed codes and passwords to identify user terminals to the master or host computer before allowing entry into the system, has proven to be naive in the face of determined efforts to break such codes. For example, identifying codes for each user terminal must be stored in the master station's computer where it is accessible to operators, possibly acting without authority, at the master station. Where the master station is connected to user terminals by public networks such as public telephone lines, interception of the codes from the user terminals is easily accomplished. Thereafter, the intercepted code can be used from any terminal to access the master station over the public lines.
What is needed is a communication security accessing system that provides protection from unauthorized access by generating a new entry code for each attempt to access the system. Only authorized user terminals should be capable of providing proper responses to a master station's verifying requests, the required response changing with each and every attempt to access the master station.
Accordingly, it is an object of this invention to provide an improved communication security accessing system and process which reliably prevents unauthorized access to the master station of a computer system.
Another object of the invention is to provide an improved communication security accessing system and process which does not rely on invariable passwords and codes for identifying user terminals.
A further object of this invention is to provide a improved communication security accessing system and process which rejects connection to a user terminal which has been moved from its authorized location.
Another object of this invention is to provide an improved communication security accessing system that provides an accounting function, keeping records of successful and unsuccessful attempts to access the master station.
Yet another object of this invention is to provide an improved communication security accessing system that is "invisible" to the access requestor.